The sunflower industry stands to benefit handsomely from two sets of genetic materials that were released by the USDA Agricultural Research Service earlier this year. The materials, which were developed by longtime ARS sunflower geneticist Jerry Miller, are available to any interested private or public sunflower breeder. They were released shortly before Miller’s retirement this past spring.

The first release was of two “maintainer” and six “restorer” Sclerotinia-tolerant confection sunflower genetic stocks. These genetic stocks were developed to provide diversity for tolerance against Sclerotinia stalk and head rot. Seed company and public breeders will utilize them to create parental lines or germplasm with the appropriate confection sunflower seed size and hull quality characteristics.

This release “was the result of the confection industry asking us to transfer the Sclerotinia resistance we had found in oilseed sunflower to confection,” Miller indicates. “Utilizing sophisticated breeding techniques and two generations in the greenhouse — plus testing under the mist irrigation system in Carrington (N.D.) — we were able to identify these lines for release.”

The materials are termed “genetic stocks” rather than “germplasm” because they were released as very early generation materials.

“However, we had excellent conditions in Fargo to test for Phomopsis resistance, as well as [at] Carrington for Sclerotinia resistance — so I am fairly confident that the genes were transferred and put into the confection type,” Miller observes. It is up to the private company breeders to utilize them in crosses and advance the quality development.

One of the lines, Miller adds, has resistance to imidazolinone and thus can be used to create hybrids that are resistant to Beyond® herbicide (i.e., Clearfield hybrids).

The second ARS release was of one “maintainer” and two “restorer” oilseed sunflower genetic stocks. These stocks are now available to provide and public breeders to use in the creation of parental lines or germplasm with resistance to the sulfonylurea herbicide known as tribenuron (i.e., ExpressSun™ hybrids).

“These lines could be utilized by companies to produce NuSun® hybrids with application of Express for weed control in minimum- or no-till farming operations,” Miller advises. “We had released populations earlier with Express resistance; but these are the first genetic stocks to be released with hybrid potential.”